Dear Adam:
When you feel helpless, you also feel a “sudden rage” that motivates you to harm yourself. The helplessness and rage go together: “when I feel helpless.. a sudden rage.. the rage, the helplessness consuming every bit of me”-
– to feel helpless means that you feel unable to make a difference in your life, to make something happen that you need to happen. To feel rage means to be motivated to make that difference, to make that something happen.
“What can be a way which can give me a quick relief, with the extreme urge to hurt myself?”- figure out right there and then something that you can do to make a difference in your life and do it, be it as small a something as can be. Examples of such some-things: (1) assert yourself with a co-worker, tell him/ her that you will not do a particular task because it is for him/ her to do, not in your job description, (2) go take a fast walk in the fresh air so to calm down, (3) talk to yourself, tell yourself that you are a good person, that you are okay, that you need some love, not hate.
What you need in those moments of self harm urges is to make a positive difference in your life, to make something positive happen, so to go from helplessness to helpfulness, that is.. to helping yourself, replacing self-harm behaviors with self-help behaviors.
If you want to elaborate on what seems to me your early life experience with helplessness: experiencing a wrong or wrongs done to you while you were unable to stop those wrongs (?), please do, and I will reply further.
anita